The invention relates to a woven hollow fiber tape with weft threads and hollow threads as the warp threads. The invention also relates to a method and a device for manufacturing the woven hollow fiber tape as well as hollow fiber bundles composed of woven hollow fiber tapes.
A woven hollow fiber tape with weft threads and hollow threads as the warp threads and a blood oxygenator manufactured therefrom are known from EP-A2-0 089 122. This known woven hollow fiber tape is the type manufactured on a so-called shuttle loom. The manufacture of such woven hollow fiber tapes is very cumbersome and hence expensive. A further disadvantage of hollow fiber tapes woven in this manner is that the weft threads cannot be pulled out again as is frequently desired. In addition, this hollow fiber tape necessarily has a monofilament (solid fiber) on each side edge to protect the hollow fibers at the edge against transverse forces and abrasion by the shuttle and to absorb tensile stresses. Such threads, however, make the manufacture of the hollow fiber tape more difficult and frequently cause problems in the finished device. Processing this known woven hollow fiber tape into a blood oxygenator and the blood oxygenator itself likewise involve disadvantages. One disadvantage of this known processing method to turn a woven hollow fiber tape into a blood oxygenator is its considerable engineering cost. Thus, a special device is required for reversal when the woven hollow fiber tape is reversed at the ends of the winder to form the next hollow fiber layer, said device making the reversal possible. In addition, the area of deflection of the hollow fibers which thus results and cannot be used is considerable, resulting in a large percentage of waste. This method also has the additional disadvantage that the winding angle to the axis of the winder is only between 30.degree. and 90.degree.. The length of the hollow fibers is then a multiple of the axial length of the winder. This results in an increased pressure loss in the interior (lumen) of the hollow fibers. In addition, if the winding angle between the axis of the winder and the woven hollow fiber tape is not modified accordingly as a function of the number of layers, the length of the hollow fibers will increase with an increasing number of layers. This produces a nonuniform flow through the hollow fibers, something which is generally undesirable.